Bevel-protractor



(No Model.) I

' R. HAKBWESSELL & F. K. RAND.

'BEVBL PROTRA'GTOR. No. 424,977. Patented Apr. 8, 1890.

graduated arc.

UNITED STATES PATENT OFFICE.

REINHOLD HAKENVESSELL AND FRED K. RAND, OF HARTFORD,

CONNECTICUT.

BEVEL- PROTRACTO R.

SPECIFICATION forming part of Letters Patent No. 424,977, dated April 8, 1890.

Application filed January 24;, 1889. Serial No. 297,379. (No model.)

To aZZ whom it may concern.-

Be it known that we, REINHOLD HAKEWES- SELL and FRED K. RAND, of Hartford, in the county of Hartford and State of Connecticut,

have invented certain new and useful Improvements in Bevel-Protraetors, of which the following is afull, clear, and exact description, whereby any one skilled in the art can make and use the same.

The object of our invention is to provide a bevel-protractor that shall be capable of a more extended use and of wider application than the protractors of the prior art.

To this end our invention consists in the combination of a sliding bar, an index-arm connected to said bar, and a triangular part to which said arm and bar are pivoted.

It further consists in the combination of the triangular part having working-edges, the index-arm pivoted to said part, the clamp adjacent to the pivot, and the sliding bar; and it further consists in details ofthe several parts and in their combination, as more particularly hereinafter described, and pointed out in the claims.

Referring to the drawings, Figure 1 is a plan View of one form of our improved device, showing the index set at zero of the Fig. 2 is a detail plan View of the same, showing the index set at fortyfive degrees and the edges of the bar and one edge of the triangle parallel to each other. Fig. 3 is a detail View in crosswise section on plane a: mof Fig. 2. Fig. 4 is a detail View of the device, illustrating one of its uses in connection with a flanged disk.

In the accompanying drawings, the letter (t denotes a triangular part, that is preferably made of steel, and has for a certain extent along each edge a straight part. Near the apexof one of the angles of this triangular part, as at b, an index-arm c is pivoted on a stud d, that has an enlarged head fitting a recessed socket on the under side of the triangular part, and a stem that extends upward through an opening in the triangular part smaller than. the head of the pivot and passing through the index-arm. This stem is threaded to receive a nut c, which forms the immediate means of clamping the arm in position by turning the nut down upon the arm.

The outer end of the arm is undercut, so that a space is left underneath it to receive the edge of a sliding bar or rule f. This bar has a lengthwise groove f into which the flanged portion on the outer end of the arm projects in such manner as to prevent the bar from having anything but a sliding movement on the arm and triangular part. A particular advantage of this construction is due to the fact that two working-edges-one a on the triangular part and another f" that is the outer edge of the bar or rule-can be set parallel to each other or at any degree of angular divergence, thus enabling the tool to be thrust in between a face-plate and the back surface of a piece of work, or held with one of the edges against a fixed part of a machinetool and the other against the work or a tool to measure the angular divergence between two surfaces or to set them at a desired degree. A. further advantage follows from the peculiar construction of the triangular part with short straight surfaces near the adjacent angles of the edge a, that enable the tool to be used, as illustrated in Fig. 4:, to reachpast a projecting flange to determine the angle between an inner surface and the outer edge ,or periphery of the flanged part.

By the term triangular part we do not mean to limit the construction of that part marked 'a to the peculiar form shown in the drawings, as the main advantages of our improvement will be present if the rule or bar is so connected to this triangular part as to provide the two working-edges facing outward and the two other edges of the triangular part adjacent to the rule and located on the opposite side of the index-arm.

The form of pivot and clamping device shown is preferred on account of the simplicity of construction; but we do not limit ourselves to this particular form.

WVe claim as our invention 1. In combination with a triangular part pivotally attached to a sliding bar at one apex and having the working-edgesand graduated scale, a sliding bar removably clamped thereto, the index-arm pivoted to the triangular part and attached to the said sliding bar, and the clamp for securing the parts temporarily, all substantially as described.

2. In combination with the triangular part having the squared ends and bearing a graduated scale, a sliding bar connected to an index-arm, the index-arm pivoted to the triangular part near the apex of one of the angles, and the clamp device for controlling the movement of the index-arm and the bar, all substantially as described.

3. The herein-described device, consisting of a triangular-shaped piece with Workingedges, the sliding bar attached to said part near one apex and to the index-arin and with its outer edge overhanging said apex, the index-bar pivoted to the triangular part, and the clamping device that controls the move ments of the index-arm and the bar, all sub stantially as described.

4. In combination with the triangular part having the squared ends, the grooved sliding bar or rule connected to the index-arm, the index-arm pivoted to the triangular part and having a flange overhanging and engaging the groove in the sliding bar, and the clamp device all substantially as described.

REINHOLD HAKEXVESSELL. FRED K. RAND.

\Vitnesses:

CHAS. L. BURDETT, ALBERT T. LITCHFIELD. 

